Daikin Altherma EPGA16DAV3 Installer's Reference Manual page 62

8 Configuration
# Code
[9.B.3] [1-0A] Averaging time:
▪ 0: No averaging
▪ 1: 12 hours
▪ 2: 24 hours
▪ 3: 48 hours
▪ 4: 72 hours
Bivalent
Bivalent
Only applicable in case of auxiliary boiler.
About bivalent
The purpose of this function is to determine which heating source
can/will provide the space heating, either the heat pump system or
the auxiliary boiler.
# Code
[9.C.1] [C-02] Bivalent: Indicates if the space heating is
also performed by means of another heat
source than the system.
▪ 0 No: Not installed
▪ 1 Yes: Installed. The auxiliary boiler
(gas boiler, oil burner) will operate
when the outdoor ambient temperature
is low. During bivalent operation, the
heat pump is turned off. Set this value
in case an auxiliary boiler is used.
▪ If Bivalent is enabled: When the outdoor temperature drops below
the bivalent ON temperature (fixed or variable based on energy
prices), the space heating by the indoor unit stops automatically
and the permission signal for the auxiliary boiler is active.
▪ If Bivalent is disabled: Space heating is only done by the indoor
unit within the operation range. The permission signal for the
auxiliary boiler is always inactive.
The switch-over between the heat pump system and the auxiliary
boiler is based on the following settings:
▪ [C‑03] and [C‑04]
▪ Electricity and gas prices ([7.4.5.1], [7.4.5.2], [7.4.5.3], and [7.4.6])
[C‑03], [C‑04], and T
calc
Based on the settings above, the heat pump system calculates a
value T , which is variable between [C‑03] and [C‑03]+[C‑04].
calc
3°C
a
b
T [C-03]+[C-04]
[C-03]
calc
T
A
T Outdoor temperature
A
T Bivalent ON temperature (variable). Below this
calc
temperature, the auxiliary boiler will always be ON. T
never go below [C‑03] or above [C‑03]+[C‑04].
3°C Fixed hysteresis to prevent too much switching between
heat pump system and auxiliary boiler
a Auxiliary boiler active
b Auxiliary boiler inactive
If the outdoor
temperature...
Space heating by
the heat pump
system...
Drops below T Stops
calc
Rises above T +3°C Starts
calc
Installer reference guide
62
Description
Description
can
calc
Then...
Bivalent signal for
the auxiliary boiler
is...
Active
Inactive
INFORMATION
▪ The bivalent operation function has no impact on the
domestic water heating mode. The domestic hot water
is still and only heated by the indoor unit.
▪ The permission signal for the auxiliary boiler is located
on the EKRP1HB (digital I/O PCB). When it is
activated, the contact X1, X2 is closed and open when
it is deactivated. See illustration below for the
schematic location of this contact.
X2M
X1M
YC Y1 Y2 Y3 Y4
# Code
N/A [C-03] Range: –25°C~25°C (step: 1°C)
N/A [C-04] Range: 2°C~10°C (step: 1°C)
The higher the value of [C‑04], the higher
the accuracy of the switch-over between
the heat pump system and the auxiliary
boiler.
To determine the value of [C‑03], proceed as follows:
1 Determine the COP (= coefficient of performance) using the
formula:
Formula
COP = (Electricity price / gas
(a)
price) × boiler efficiency
(a) Make sure to use the same units of measurement for the
electricity price and gas price (example: both c€/kWh).
2 Determine the value of [C‑03] using the graph:
COP
6
5
4
3
2
1
0
-14 -12 -10 -8 -6 -4 -2
Example:
a [C‑03]=2.5 in case of COP=3 and LWT=35°C
b [C‑03]=10.5 in case of COP=3 and LWT=55°C
NOTICE
Make sure to set the value of [5‑01] at least 1°C higher
than the value of [C‑03].
Electricity and gas prices
EPGA11~16DAV3 + EAVZ16S18+23DA6V+9W
OFF ON
SS1
Description
Example
If:
▪ Electricity price: 20 c€/kWh
▪ Gas price: 6 c€/kWh
▪ Boiler efficiency: 0.9
Then: COP = (20/6)×0.9 = 3
0 2 4 6 8 10 12 14
2.5 (a) 10.5 (b)
Daikin Altherma – Low temperature split
4P556075-1 – 2019.02